Process of dissolving sodium silicate



E. A. TAYLOR. PROCESS 0F DISSULVING SODIUM SILICATE.

APPLICATION FILED OCT. l0, |9I.

Patented May 2V, 1920.

f description refer-rin lplication of this met revision 40 p UNITED STATES PATENT-OFFICE.

I EDWARD A.. TAYLOR, 0F CLEVELAND, OHIO, ASSIGNOR TO THE GRASSELLI CHEMICAL COMPANY, 0F CLEVELAND, OHIO, A CORPORATION OF OHIO.

PROCESS OF DISSOLVING- SODIUM SILICATE.

Specication of Letters Patent.

Application illed October 10, 1917. Serial-No. 195,708.

To all whom it may concern: v

Be it known that I, EDWARD A. TAYLOR, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new anduseful Im rovement in Processes of Dissolving So ium silicate, of which the following is a specificatiom'the principle of the invention being herein explained and the best mode in which I have contemplated apply` ing that principle, so as to distinguis it from other inventions.

, The subject of the presenty application is a method of treating a solid material with a liquid, either for the purpose of securing a suspension of the former in the latter or or dissolving the solid in the liquid, the present sodium silicate, together with a preferred form of apparatus for carrying out this method. 1 l

Commercial sodium silicate, which is ordinarily prepared by and alkaline materials in a suitable furnace, is a solid material which is practically .insoluble in water at ordinary tem eratures and under ordinary conditions. or use in various arts it is necessary, however, to dissolve sodium silicate in water, and considerable diiiiculty7 fecting this so ution on a commercial scale. In fact it may be said that this has been accomplished commercially only by the employment of comparative y intricate processes, whichv involve the use of-complicated and expensive machinery.

One object of the resent invention is a of a metho of dissolvin sodium silicate in water without the'use o complicated or expensive machinery and without the use of expensive means of agitating the bod during its dissolution. To the accom-` plis ment of the foregoing and related ends, said invention,then, consists of the means hereinafterfully described and particularly pointed out in the claims. p

The annexed drawing and the following description set forth in detaill certain means out the invention, mode illustrating, various ways in and one mode of carrying such disclosed means an however, but one' of the particularly to one apod to the dissolving ofthe fusion of siliciousA has been experienced in ef` For convenience and clearness of description I- will preferably describe my improved method in connection with an improved form of apparatus, which is shown in the accompanying drawings. In said annexed drawings Figure 1 is a transverse vertical section Patented May 25, 192e. i

showing certain parts and connections in Y elevation; Fig. 2 is a plan view of the apparatus shown in F igrl; and Fig. 3 is a side elevation of the upper end of the apparatus, tovether with the connections.

ieferring now to Fig. 1, there is shown a suitable supporting frame 1, upon which is mounted a substantially cylindrical chamber 2 arranged in a vertical position and having a curved bottom 3 upon which there is Vmounted in suitable bearings an agitating screw 4, which is held at its upper end in a yoke 5 suitabl attached to the top or' cover 6 of the cylin er. This agitating screw 4 is inclosed in a cylindrical casin 7, which terminates short of the lower an .upper end of the agitator and is open at both ends to the interior of the chamber2. The agitator is driven by means of a shaft 8 extending through the cover 6 and bearing a gear 9 driven by a gear 10 on a driving shaft 11.

. Mounted adjacent to the bottom 3 of the cylinder is a screen or grille 12 extending horizontally across the cylinder and serving to support the charge of silicate or other material when it is introduced into the chamber. This grille 12 is suitably supported upon brackets 13 attached to the walls of the cylinder 2. In the top 6 there is an opening which is normally closed by means ofa manhole cover 14, and through this opening the charge of silicate is first introduced into the apparatus. Also `extending through the cover 6 are two conduits 15 and 16, the first conduit being connected to a coil 17 disposed in the chamber 2 adjacent to the walls of the same. This coil 17 is provided with adrain pipe 18 extending through ythe side of the chamber and is adapted to have steam pas therethrough during the operation of the apparatus. The'other of the two conduits, 16 discharges directly into the chamber 2 and is provided with connections 18, 19 and 20, controlled by valves 18', 19 and 20', which are adapted to carry water, steam and air. respectively. The bottom of the cylinder 2 is similarly provided with a drain pipe 21 controlled by means of a valve 22 for removing the liquid contents of the cylinder after each operation.

Assuming now that a charge of sodium silicate is to be dissolved according to my improved method, the solid material is first chargedv into the chamber to a point below the top of the cylinder 7 around the agitator 4. I Vater is then run into the chamber 2 through the pipes 1S and 16 to any desired level, which will be adjacent to the top of the c linder, after which the manhole is close by the cover 14: and retaining means for the same firmly secured. Steam or other heating medium is then caused to circulate through the closed coil 17 until the pressure generated on the inside of the apparatus by the heat of this coil is within a few pounds of the pressure of the steam itself, and suitable gages may be connected to the steam inlet pipe 15 and to` the interior of the chamber A2l for determining these relative pressures. During this heating of the contents of the chamber 2 the agitator is run eithercontinuously or intermittently a suficient amount to provide a slow circulation of the material through the chamber 2 and thus thoroughly mix the water and solid matter therein. rlhis agitation prevents the settling and accumulation of any impurities at the bottom of the machine as well as the formation of lumps which prevent free access of the solution to the solid material. The formation of lumps slows down the dissolving of the material and prevents accurate samplings of the contents of the apparatus.

After the pressurev in the chamber `2 has been brought to approximately the pressure of the steam in the coil 17, steam, or some other heating medium which is inert to the sodium silicate, is introduced through the lines 19 and 16 and thus brought directly in Contact With the water and the sodium sili- 21 show the degree of concentration desired,

WhenA the solution is drawn oif through that connection, leaving 1n some cases undissolved material on the grille 12. This residue is of course treated in the next batch, and in ordinary operation it is not expected that one charge will be entirely dissolved at any one time, it being necessary ordinarily to add about one-third of the original charge after each operation as this gives satisfactory concentration of the solution.

Other modes of applying the principle 0f my invention may be employed instead of the one explained, change being made as regards the method herein disclosed, provided the step or steps stated by any of the following claims o1' the equivalent of such stated step or steps be employed.

I therefore particularly point out and distinctly claim as my invention.

1. In a method of dissolving a soluble silicate, the steps which consist in passing a solvent over and through an excess of soluble silicate and heating such solvent with a gas chemically inert to such soluble silicate.

2. In a method of dissolving a soluble silicate, the steps which consist in acting upon a large excess of soluble silicate with a solvent, maintaining such soluble silicate in a quiescent condition and passing such solvent gently through the .same and heating such solvent during such passage.

3. In a method of dissolving a soluble silicate, the steps which consist in acting upon a large excess of soluble silicate with a solvent, maintaining such soluble silicate in a quiescent condition and passing such solvent gently through the same and heating such solvent during such passage with a gas chemically inert to such soluble silicate.

4. In a method of dissolving a soluble alkaline silicate or the like, the steps which consist in heating an excess of soluble silicate in the presence of water with steam, maintaining such soluble silicate in a quiescent condition and slowly forcing such water through such soluble silicate.

5. In a method of dissolving a soluble alkaline silicate or the like, the steps which consist in heating an excess of soluble silicate in the presence of water with steam, maintaining such soluble silicate in a quiescent condition, slowly forcing such water through such soluble silicate, and then drawing off the solution when the required strength is attained.

Signed by me, this 3rd day of Oct. 1917.

' EDWARD A. TAYLoR. 

